Why Your Air Conditioner Makes a Loud Noise When Turning Off

Any type of loud noise coming from your air conditioner can seem worrisome. When an air conditioner makes loud noises, it could stem from various reasons. Sometimes, the slamming sound or popping sound you hear can even be normal.

To completely diagnose the issue, you may need an HVAC technician to check it out. However, there are some things to look for to maybe figure out on your own.

Read on to learn more about how to figure out what’s causing a loud noise when turning off your air conditioning unit.

Why Your Air Conditioner is Making a Loud Noise When Turning Off Inside

1. Check your air filter

When an air filter becomes too restrictive or dirty, it can end up slamming against the grille. This can be as simple as cleaning your air filter out and making sure it’s fitting the way it’s supposed to and is clean.

Depending on the air conditioner you have and the type of air filter, you can usually just rinse it under some water. Let it dry and then put it back on. If the problem clears up then you know it was just your filter.

Most air conditioners will have a light that will show up if your air filter needs to be clean. Once you do clean your air filter, you may even be able to breathe better as it helps filter airborne contaminants.

2. Damper closing can be noisy

Some air conditioning systems have a damper to alter the amount of airflow that circulates different areas of your home. When the damper closes after you shut the AC off, that could cause the slamming noise. If this is the issue, you don’t have to worry as it’s just a normal operation.

3. Contracting ductwork; normal but loud

When your ductwork expands and contracts, it can become a bit noisy. This could be a simple explanation of why you hear noises when you shut your AC off. If you have sheet metal ductwork this can be more common.

When the temperature changes it can cause expansion and contractions. If this is loud and bothersome for you, you can insulate your ductwork. This can be done by an HVAC professional.

4. Air handler messing up

The air handler is what the name sounds like; it handles the air that is pumped in via the blower fan. When there is a problem with the air handler, it can cause the blower wheel to bang against other components in your AC unit. It’s also called the inside AC unit.

If the other issues are ruled out and your air conditioner turns on with noise still, this is one you may want to get checked out or want to replace.

Of course, these aren’t for sure signs; however, if you notice your airflow is inconsistent, your electric bill is rapidly rising, or the air handler freezes during the summer, that could be the issue when your ac makes a loud noise.

Why Your Air Outdoor Unit is Making a Loud Noise When Shutting Off

1. Compressor support springs losing balance

When the compressor’s support rings on your outdoor unit reach the end of its life span, it loses balance. The result is the refrigerant pump ends up banging against the case of the compressor.

When your air conditioner turns on and the fans are running but there is no cool air, this is a good way to tell if the compressor support springs are the issue. If so, you may want to replace the compressor and see if that does the trick; if not, hiring an HVAC professional would be ideal to see what’s going on with your air conditioning system.

2. Fan issues may need repair

The fan on your outdoor AC unit may need to be replaced or repaired. Sometimes the loose components can cause lead to a noisy ac with banging sounds. If your outdoor fan is the problem, you may notice rattling, buzzing, or humming noises along with not being able to keep your home as cool as normal.

If all you notice is warm air coming from your ac unit, that’s an indication it could have something to do with the fan. You can replace your outdoor fan and see if your ac works better after.

When Should I Call an HVAC Professional?

Air conditioning noises can be worrisome. If you are not familiar with working on an indoor unit or outdoor unit, it’s worthwhile to hire a professional. When there are any loose parts or loud slamming noises, it’s better to have someone with experience work on your ac system.

With an ac making noise, you may panic thinking you’re going to have to spend a lot of money; however, it’s best to have the problem looked at before it turns into anything worse.

If you do have experience but you have tried everything, it’s a good idea to get a second opinion to see what’s causing the noisy air conditioner issues.

Final Thoughts

When you notice a loud slamming noise or other loud sounds coming from your outside unit or indoor unit, be sure to take a look to find the issue ASAP. Prolonging the issue can lead to irreversible problems. Start with simple solutions and go from there.

Start with your air filter. Clean it and see if that solves the problem. Air filters can cause all sorts of issues on their own when they are dirty. From there, you can try the blower wheel or see if it’s the damper closing.

It’s ideal to keep an air filter clean as it helps the ac overall function, provides efficient cool air, and even reduces the contaminants in the air that you and your family breathe in.

Hiring an HVAC technician can benefit if you don’t have time to figure out the loud sound and need ac repair fast. Once you get to the root of the problem, you will be able to relax and cool down easier without the slamming noise. It may also make sense to look into our roundup of best quiet wall AC units.

About Heather Burdo

With almost a decade of experience with digital marketing, Heather Burdo has gained diverse experience across a multitude of industries. You can reach her at [email protected]

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